CTI GG SO2 User manual

Brand: CTI

Model: GG SO2

Type: User manual

Installation and Operation Manual

GG-SO2

SULFUR DIOXIDE GAS SENSOR

2GG-SO2

Warning

Use this product only in the manner described in this manual.

If the equipment is used in a manner not specied by Calibration

Technologies, the protection provided by the equipment may be impaired.

This equipment should be installed by qualied personnel.

GG-SO2 3

Table of Contents

General Description .....................4

Installation .............................4

Locating the Sensor ...................4

Installation Guidelines .................5

Wiring ...............................6

Operation .............................. 7

Start-Up .............................7

Calibration ...........................7

Maintenance ...........................9

Specications ..........................10

Warranty ..............................11

For technical support, contact:

Calibration Technologies

920 N Tradewinds Pkwy

Columbia, MO 65201

866-394-5861

[email protected]

www.ctiengineering.com

4GG-SO2

General Description Installation

The GG-SO2 sensor is a +24 VDC, three-wire, 4/20

mA sensor for sulfur dioxide which utilizes proven

electrochemical sensor technology for fast and

accurate detection. The 0-20 ppm detection range of

the GG-SO2 provides real-time continuous monitoring

of Sulfur dioxide concentrations accurately down to 1

ppm without false alarms.

The GG-SO2 provides an industry standard linear 4/20

mA output signal compatible with most gas detection

systems and PLCs. The output signal is not aected

by drastic temperature and moisture variations that

occur during daily process cycles.

The transmitter circuit board is sealed in potting

compound, protecting sensitive electronic

components and copper tracing from corrosion. The

specially vented chemical-resistant polycarbonate (or

optional stainless steel) enclosure protects the sensor

from accidental damage, weather and direct hose-hits

from clean-up crews.

Locating the sensor

One of the most important considerations when

installing GG-SO2 sensors is that they must be easily

accessible for calibration and maintenance.

Sulfur dioxide is almost twice as heavy as air and

will tend to accumulate in low-lying areas in poorly

ventilated rooms. For optimum personnel protection

(representative concentration reading that an

employee would be exposed to), mount the sensor

at a height no higher than the breathing zone of the

employees. It would typically be about 4 to 5 feet

o the ground, which also allows easy access. As a

general rule of thumb, try to mount sensors within 30

feet of SO2 gas sources.

Caution: Remove protective label.

The sensor is shipped with a label installed over

the gas diusion port of the electrochemical cell to

preserve cell life. The cell will not detect SO2 vapors

with this label installed. Remove label and discard

during installation.

GG-SO2

Installation Guidelines:

• Remove and discard protective cell cover

• Always mount the sensor vertically.

• Must be easily accessible for calibration and

maintenance.

• Mount the sensor close to the potential leak source.

• For optimum personnel protection, mount sensor

in the “breathing zone” (5 feet above oor).

• Take air movement and ventilation patterns into

account.

• To prevent electrical interference, keep sensor and

wire runs away from mercury vapor lights, variable

speed drives, and radio repeaters.

• Protect sensor from physical damage (forklifts, etc).

• If mounting on a wall with studs, the mounting

screws should be screwed into the studs.

• Never mount the sensor in CA (controlled

atmosphere) rooms because normal atmospheric

levels of oxygen are required for operation.

• For highly critical locations more than one sensor

should be installed in each room.

• Mount sensor enclosure through the mounting

holes as shown in Figure 1.

2.0"

6.5"

6.8"7.75"

Figure 1: Mounting Dimensions

6GG-SO2

Wiring

Electrical wiring must comply with all applicable codes.

Electrical Power: 24 VDC regulated, 350 mA.

Output: Linear 4/20 mA output. Monitoring

equipment may have a maximum input impedance of

700 ohms.

Cable Recommendation: 20/3 shielded cable

(General Cable C2525A or equivalent). Length of cable

to sensor should be no greater than 1,500 feet.

Monitoring: Monitoring equipment must be

congured to indicate a fault if the signal is below 1

mA. All signals over 20 mA must be considered high

gas concentrations. Alarm setpoints should not be

lower than 10% of full-scale range.

Wiring Guidelines:

• Always use 3-conductor, insulate, stranded,

shielded copper cable.

• Do not pull sensor wiring with AC power cables.

This can cause electrical interference.

• If cable runs cannot be made without a splice, all

splice connections should be soldered.

• Ground the shield at the main control panel.

Connect the shield wire in the sensor terminal

block labeled SHLD.

• Always disconnect power at the controller before

performing any wiring at the sensor.

• To maintain NEMA/IP rating of the enclosure,

conduit ttings of the same rating or better must

be used.

To signal input of monitoring equipment

To +24V terminal of power supply

To ground terminal of power supply

To case (earth) ground of monitoring equipment

Terminal Block Plug (Field Wiring):

SHLD: To case (earth) ground of monitoring equipment

GND: To ground terminal of power supply

+24V: To +24V terminal of power supply

SIG: To signal input of monitoring equipment

Figure 2:

GG-SO2

Operation

Start-Up

Allow 60 seconds for power up time delay of sensor

to end (green power LED will ash during power up).

Sensor can be response tested after power-up, but

best to wait 1 hour to zero or span sensor after power

up.

Start-Up Test:

One person exposes each sensor to calibration

gas. The second person stays at the control unit to

determine that each sensor, when exposed to the

target gas, is connected to the proper input and

responds, causing appropriate alarm functions.

LED functions (see Figure 3 on page 8)

Calibration

The GG-SO2 sensor comes factory calibrated and

should require only minimal adjustments after

installation. There are two pots on the preamp that

are used for calibration (see Figure 3).

Note: Never measure sensor output in mA. Always

use mVDC or VDC voltmeter settings.

Zero Calibration: After the sensor is installed and

has been powered up for 1 hour, the unit can be zero

calibrated by the following:

• Be sure the unit is in clean air. If unsure, apply Zero

Air gas at 0.5 to 0.8 L/min.

• Adjust the Zero pot until the sensor outputs 40 mV

from Test [-] to Test [+] (see Figure 3).

Span Calibration: If span adjustment is required, use

the following procedure:

• To enter calibration mode (disables all ltering and

averaging), turn the Zero pot clockwise 1/4 turn and

then back again. Successful entry into calibration

mode will be indicated by the Power (green) LED

blinking twice per second. Calibration mode will

time out automatically after 4 minutes.

• Apply span gas at 0.5 to 0.8 L/min (span gas must

be in air, not nitrogen or other carrier).

• Sensor should react to gas within 15 seconds.

• Once the output signal has peaked (or 3 minutes

maximum) adjust the Span pot until the correct

output is achieved (see Figure 3). With full-scale

span gas, the calculated span value is 200 mV.

((span gas / sensor range * 16 + 4) (mA output))

Note: Below are a few response characteristics which

may be an indication that the gas sensor is at or near

the end of its useful life. If any of these are observed,

the cell should be replaced:

• Slow response to / recovery from calibration gas.

• Failure of the output to reach 50% of the calibration

gas value prior to span adjustment if last calibration

was 6 months ago or less.

• Unable to achieve correct output during span.

8GG-SO2

Figure 3: Sensor board components and zero/span adjustment

Sensor Cable plugs into socket here

Span adjustment

Zero adjustment

40-200 mV

mVDC

Black Red

Fault (red) LED:

• On steady if supply voltage is

less than 10VDC.

Status (amber) LED:

• Blinks once per second if RFI is

detected.

Power (green) LED:

• On steady to Indicate Power.

• Blinks once per second for 60

seconds during power-up.

• Blinks once per second

continuously if supply voltage

is too low.

• Blinks twice per second in

calibration mode (4 minute

timeout delay).

Cell

GG-SO2

Maintenance

The GG-SO2 was designed for long life and minimal

maintenance. For proper operation it is essential

that the test and calibration schedule be adhered to.

Calibration Technologies recommends the following

maintenance schedule.

Maintenance Guidelines:

• The sensor is shipped with a factory calibration.

Sensor should be calibrated 6 months from

purchase date.

• Calibrate the detector at least once every 6 months.

• Calibration should be performed with certied

calibration gas. Calibration kits and replacement

cylinders are available from Calibration

Technologies.

• All tests and calibrations must be logged.

• Always disconnect power at the controller before

performing any wiring at the sensor.

Sensor Life:

These electrochemical cells are extremely reliable, but

several things can cause the cell chemicals to become

depleted including:

• a period of time

• exposure to high temperatures

• continuous, long term exposure to sulfur dioxide

When the cell becomes depleted, the unit will give no

indication of failure other than that the sensor will not

respond. For this reason, it is absolutely essential

that these sensors be calibrated on a regular basis.

Typical cell life will be two to three years. When the cell

becomes depleted, a replacement cell can be obtained

from Calibration Technologies. Simply unplug the cell’s

ribbon cable from the transmitter, pull the old cell

from the spring clip, discard the old cell and replace it

with a new one.

Replacement cell order #:

GG-SO2-RC

10 GG-SO2

Specications

Input Power: +24 VDC, 350 mA

Detection Principle: Electrochemical

Detection Method: Diusion

Gases: Sulfur Dioxide (SO2)

Ranges:

0/20 ppm (standard)

Output Signal:

Linear 4/20 mA (max input impedance: 700 Ohms)

Response Time:

T50 = less than 30 seconds

T90 = less than 90 seconds

Accuracy:

+/- 5% of full-scale, but dependent on calibration gas

accuracy and time since last calibration

Zero Drift: Less than 0.1% of full-scale per month,

non-cumulative

Span Drift: Application dependent, but generally less

than 3% per month

Linearity: +/- 0.5% of full-scale

Repeatability: +/- 1% of full-scale

Temperature Range:

-40°F to +122°F (-40°C to +50°C)

Humidity Range: 5% to 100% condensing

Dimensions: 7.7” high x 6.7” wide x 3.8” deep

Weight: 3.0 lbs

Power (green) LED: Blinks once per second for 60

seconds during power-up. If supply voltage is too low

(<10VDC) or improperly grounded, will blink once

per second continuously. Stays on steady to indicate

power. Blinks twice per second in calibration mode

(4-minute timeout delay).

Status (amber) LED: Blinks once per second if RFI

(radio frequency interference) is detected.

Fault (red) LED: Stays on steady if supply voltage is

too low (<10VDC) or hardware failure.

Wiring Connections: 3-conductor, shielded, stranded,

≥ 20 AWG cable (General Cable C2525A or equivalent)

up to 1500 ft.

Terminal Block Plug (Field Wiring): 26-12 AWG,

torque 4.5 lbs-in.

Enclosure: Injection-molded, NEMA 3RX washdown-

duty, polycarbonate sensor housing with hinged lid

and captive screw. For non-classied areas.

Optional 18 GA, NEMA 3RX washdown-duty stainless

steel enclosure with hinged lid and captive screw. For

non-classied areas.

Certication:

SGS Listed:

Conforms to UL 61010-1

Certied to CSA C22.2 No. 61010-1

GG-SO2

Limited Warranty & Limitation of Liability

Calibration Technologies, Inc. (CTI) warrants this product to be free from defects in material and workmanship

under normal use and service for a period of two years (including the cell), beginning on the date of shipment

to the buyer. This warranty extends only to the sale of new and unused products to the original buyer. CTI’s

warranty obligation is limited, at CTI’s option, to refund of the purchase price, repair, or replacement of a

defective product that is returned to a CTI authorized service center within the warranty period. In no event shall

CTI’s liability hereunder exceed the purchase price actually paid by the buyer for the Product.

This warranty does not include:

a) routine replacement of parts due to the normal wear and tear of the product arising from use;

b) any product which in CTI’s opinion, has been misused, altered, neglected or damaged by accident or abnormal

conditions of operation, handling or use;

c) any damage or defects attributable to repair of the product by any person other than an authorized dealer or

contractor, or the installation of unapproved parts on the product

The obligations set forth in this warranty are conditional on:

a) proper storage, installation, calibration, use, maintenance and compliance with the product manual

instructions and any other applicable recommendations of CTI;

b) the buyer promptly notifying CTI of any defect and, if required, promptly making the product available for

correction. No goods shall be returned to CTI until receipt by the buyer of shipping instructions from CTI; and

c) the right of CTI to require that the buyer provide proof of purchase such as the original invoice, bill of sale or

packing slip to establish that the product is within the warranty period.

THE BUYER AGREES THAT THIS WARRANTY IS THE BUYER’S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF

ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY

OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. CTI SHALL NOT BE LIABLE FOR ANY SPECIAL,

INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING LOSS OF DATA, WHETHER

ARISING FROM BREACH OF WARRANTY OR BASED ON CONTRACT, TORT OR RELIANCE OR ANY OTHER THEORY.

ctiengineering.com | 866-394-5861

GG-SO2-DOC1-3

20211103

CTI GG SO2 User manual

CTI GG SO2 User manual

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